Abstract : When a graphene layer is suspended over a circular hole, the graphene acts as a drum. Likewise, a suspended nanotube vibrates as a guitar string. However, one important difference between a graphene resonator and a music drum is the mass, since graphene is only one atom thick. Another difference is the quality factor Q, which becomes extremely large in graphene resonators at cryogenic temperature (Q above 1 million). Because of this combination of low mass and high quality factor, the motion is enormously sensitive to the environment – the mechanical eigenstates are extremely fragile and easily perturbed by the measurement. But, if graphene and nanotube resonators can be properly harnessed, they become incomparable sensors of mass and force. From a fundamental point of view, nanotube and graphene resonators are very interesting to study the physics of noise and dissipation.
ICFO – The Institute of Photonic Sciences, Castelldefels (Barcelona), Spain